Association of CT Findings With Perineural Invasion in Gallbladder Cancer: Preliminary Assessment

Advances and current research status of early diagnosis for gallbladder cancer

Gallbladder cancer (GBC) is the most common malignant tumor in the biliary system, characterized by high malignancy, aggressiveness, and poor prognosis. Early diagnosis holds paramount importance in ameliorating therapeutic outcomes. Presently, the clinical diagnosis of GBC primarily relies on clinical-radiological-pathological approach. However, there remains a potential for missed diagnosis and misdiagnose in the realm of clinical practice. We firstly analyzed the blood-based biomarkers, such as carcinoembryonic antigen and carbohydrate antigen 19-9. Subsequently, we evaluated the diagnostic performance of various imaging modalities, including ultrasound (US), endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography/computed tomography (PET/CT) and pathological examination, emphasizing their strengths and limitations in detecting early-stage GBC. Furthermore, we explored the potential of emerging technologies, particularly artificial intelligence (AI) and liquid biopsy, to revolutionize GBC diagnosis. AI algorithms have demonstrated improved image analysis capabilities, while liquid biopsy offers the promise of non-invasive and real-time monitoring. However, the translation of these advancements into clinical practice necessitates further validation and standardization. The review highlighted the advantages and limitations of current diagnostic approaches and underscored the need for innovative strategies to enhance diagnostic accuracy of GBC. In addition, we emphasized the importance of multidisciplinary collaboration to improve early diagnosis of GBC and ultimately patient outcomes. This review endeavoured to impart fresh perspectives and insights into the early diagnosis of GBC.

Machine learning model based on preoperative contrast-enhanced CT and clinical features to predict perineural invasion in gallbladder carcinoma patients

BACKGROUND

Perineural invasion (PNI) is an independent prognostic risk factor for gallbladder carcinoma (GBC). However, there is currently no reliable method for the preoperative noninvasive prediction of PNI.

METHODS

This retrospective study included 180 patients with pathologically diagnosed GBC who underwent preoperative contrast-enhanced CT between January 2022 to December 2023 at one high-volume medical center from China. K-Nearest Neighbors (KNN), LightGBM (LGB), Logistic Regression (LR), XGBoost (XGB), Naive Bayes (NB), and Support Vector Machine (SVM) were employed to develop prediction models. The Shapley additive explanations (SHAP) were used to visualize models and rank the importance of features associated with PNI.

RESULTS

Total bilirubin, CA19-9, imaging liver invasion, vascular invasion, T staging and N staging were identified as risk factors for PNI (P < 0.05). The LightGBM model demonstrated the improved performance in the testing set, with the AUCs of 0.886 and 0.795 in the training and testing sets, respectively. In four machine learning algorithms prediction models demonstrated improved performance included three imaging features (imaging T staging, N staging, and vascular invasion) and two clinical features (TBIL and CA19-9). When these features were employed to develop the prediction models, the LightGBM model exhibited the higher performance than other machine learning modes in the testing set, with AUCs of 0.843 and 0.802, and ACCs of 0.786 and 0.759 in the training and testing sets, respectively.

CONCLUSION

A machine learning-based prediction model integrating contrast-enhanced CT imaging and clinical features demonstrates good performance and stability in the noninvasive preoperative identification of PNI status in GBC patients.

Update on the Role of Imaging in the Diagnosis, Staging, and Prognostication of Gallbladder Cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy with dismal prognosis. GBC is characterized by marked geographic predilection. GBC has distinct morphological types that pose unique challenges in diagnosis and differentiation from benign lesions. There are no specific clinical or serological markers of GBC. Imaging plays a key role not only in diagnosis and staging but also in prognostication. Ultrasound (US) is the initial test of choice that allows risk stratification in wall thickening and polypoidal type of gallbladder lesions. US findings guide further investigations and management. Computed tomography (CT) is the test of choice for staging GBC as it allows comprehensive evaluation of the gallbladder lesion, liver involvement, lymph nodes, peritoneum, and other distant sites for potential metastases. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography allow better delineation of the biliary system involvement. Contrast-enhanced US and advanced MRI techniques including diffusion-weighted imaging and dynamic contrast-enhanced MRI are used as problem-solving tools in cases where distinction from benign lesion is challenging at US and CT. Positron emission tomography is also used in selected cases for accurate staging of the disease. In this review, we provide an up-to-date insight into the role of imaging in diagnosis, staging, and prognostication of GBC.

Dual-energy CT in differentiating benign gallbladder wall thickening from wall thickening type of gallbladder cancer

OBJECTIVE

To evaluate the performance of dual-energy computed tomography (DECT) in differentiating non-acute benign from malignant gallbladder wall thickening (GBWT).

METHODS

This prospective study comprised consecutive adults with GBWT who underwent late arterial phase (LAP) and portal venous phase (PVP) DECT between January 2022 and May 2023. The final diagnosis was based on histopathology or 3-6 months follow-up imaging. DECT images in LAP and PVP were assessed independently by two radiologists. The demographic, qualitative, and quantitative parameters were compared between two groups Multivariate logistic regression was performed to determine the association between the aforementioned factors and malignant GBWT.

RESULTS

Seventy-five patients (mean age 56 ± 12.8 years, 46 females) were included. Forty-two patients had benign, and 33 had malignant GBWT. In the overall group, female gender (p = 0.018), lymphadenopathy (p = 0.011), and omental nodules (p = 0.044) were significantly associated with malignant GBWT. None of the DECT features differed significantly between benign and malignant GBWT in overall group. In the xanthogranulomatous cholecystitis (XGC, n = 9) vs. gallbladder cancer (GBC) (n = 33) subgroup, mean attenuation value at 140 keV LAP VMI was significantly associated with malignant GBWT [p = 0.023, area under curve 0.759 (95%CI 0.599-0.919)].

CONCLUSION

DECT-generated quantitative parameters do not add value in differentiating non-acute benign from malignant GBWT. However, DECT may have a role in differentiating XGC from GBC in a selected subgroup of patients. Further, larger studies may be necessary to confirm these findings.

CLINICAL RELEVANCE STATEMENT

In patients with non-acute gallbladder wall thickening in whom there is suspicion of xanthogranulomatous cholecystitis (XGC), DECT findings may allow differentiation of XGC from wall thickening type of gallbladder cancer.

KEY POINTS

Differentiation of benign and malignant gallbladder wall thickening (GBWT) at CT is challenging. Quantitative dual energy CT (DECT) features do not provide additional value in differentiating benign and malignant GBWT. DECT may be helpful in a subgroup of patients to differentiate xanthogranulomatous cholecystitis from gallbladder cancer.

Outcomes of Self-expandable Metal Stents in Patients With Unresectable Gallbladder Cancer Undergoing Percutaneous Biliary Drainage

Background

Biliary obstruction in gallbladder cancer (GBC) is associated with worse prognosis and needs drainage. In patients with biliary confluence involvement, percutaneous biliary drainage (PBD) is preferred over endoscopic drainage. However, PBD catheters are associated with higher complications compared to endoscopic drainage. PBD with self-expandable metal stents (SEMS) is desirable for palliation. However, the data in patients with unresectable GBC is lacking.

Materials and methods

This retrospective study comprised consecutive patients with proven GBC who underwent PBD-SEMS insertion between January 2021 and December 2022. Technical success, post-procedural complications, clinical success, duration of stent patency, and biliary reinterventions were recorded. Clinical follow-up data was analysed at 30 days and 180 days of SEMS insertion and mortality was recorded.

Results

Of the 416 patients with unresectable GBC, who underwent PBD, 28 (median age, 50 years; 16 females) with PBD-SEMS insertion were included. All SEMS placement procedures were technically successful. There were no immediate/early post-procedural complications/deaths. The procedures were clinically successful in 63.6% of the patients with hyperbilirubinemia (n = 11). Biliary re-interventions were done in 6 (21.4%). The survival rate was 89.3 % (25/28) at 30 days and 50% at 180 days. The median follow-up duration was 80 days (range, 8-438 days).

Conclusion

PBD-SEMS has moderate clinical success and 6-months patency in almost half of the patients with metastatic GBC and must be considered for palliation.

Proposal for a new morphological "combined type" of gallbladder cancer: description of radiopathological characteristics and comparison with other morphological types

OBJECTIVE

To describe the radiopathological characteristics of a new morphological "combined type" of gallbladder cancer (GBC) and compare it with the mass replacing gallbladder and thickening types of GBC.

MATERIALS AND METHODS

The imaging and pathological details of consecutive patients with GBC between August 2020 and December 2022 were retrospectively reviewed. Two radiologists reviewed computed tomography/magnetic resonance imaging in consensus for the morphological type of GBC. The radiologists classified GBC as mass replacing gallbladder, wall thickening, and combined type. The combined type was defined as a mass arising from the thickened wall of an adequately distended gallbladder that extended exophytically into the adjacent liver parenchyma. The presence of calculi, site, and size of lesion, biliary/portal vein involvement, liver, lymph node, and omental metastases was compared among the various types. The pathological characteristics were also compared.

RESULTS

Of the 481 patients (median age 55 years, 63.2% females) included in the study, mass replacing gallbladder, wall thickening, and combined-type GBC were seen in 42.8% (206/481), 40.5% (195/481), and 16.6% (80/481) of patients, respectively. In the combined type of GBC, biliary/portal vein involvement was seen in 63.7% (51/80) and 7.5% (6/80) of patients. Liver, lymph node, and omental metastases were seen in 67.5% (54/80), 40% (32/80), and 41.2% (33/80) patients, respectively. Liver metastases were significantly more common in the combined type (p = 0.002). There were no significant differences in pathological characteristics among the various types.

CONCLUSION

Combined-type GBC is less common than the mass replacing gallbladder and thickening types and is associated with a higher risk of liver metastases.